Introduction

In order to ensure the quality of some solid preparations, or to achieve some special purpose, such as controlled release, enteric, etc., need to be wrapped in the surface of the appropriate material into a coating film, so that the drug and the outside world to isolate, this process is called coating, the material for the coating system excipients.

The necessity of coating or the type of coating is determined by the nature of the drug and the purpose for which it is to be used. Coating can be considered for the following reasons:

1. API is unstable, easily changed when in contact with oxygen, carbon dioxide, moisture, etc. in the air for a long period of time, or is unstable when exposed to light, or is highly susceptible to moisture absorption in the air;

2. API has a bad smell, unpleasant taste, nausea, vomiting in swallowing, as well as stomach irritation;

3. The need to control the release of API, such as in the gastric juice is easy to be destroyed, after coating so that it is released in the intestines;

4. Control the diffusion of the drug, the release rate, in order to achieve controlled release;

5. To overcome the contraindications, adjusting the efficacy of the drug, and so on.

Subtypes of Coating System Excipients

Film Formers

Film formers are the primary components of coating systems and create a thin, continuous film around the dosage form. Common film formers include hydroxypropyl methylcellulose (HPMC), ethyl cellulose (EC), and polyvinyl alcohol (PVA). These excipients provide excellent moisture barrier properties, controlled release characteristics, and mechanical strength to the coating.

Plasticizers

Plasticizers are additives that enhance the flexibility and elasticity of the coating film. They prevent cracking or peeling of the coating during the manufacturing process or subsequent handling. Examples of plasticizers include polyethylene glycol (PEG), triethyl citrate (TEC), and diethyl phthalate (DEP).

Opacifiers

Opacifiers are used to improve the visual appearance and color uniformity of the coated dosage forms. Titanium dioxide is a commonly used opacifier that provides a white or opaque color to the coating.

Colorants

Colorants are added to coating systems to impart a specific color or shade to the dosage form. They enhance product identification, branding, and differentiation. Examples of colorants include iron oxides, FD&C dyes, and natural pigments.

Application

Tablets

Coating excipients find extensive application in tablet formulations. Film coatings provide a protective layer that masks the taste, facilitates swallowing, and enhances the stability of the tablet. They can also be used to achieve modified release profiles or to enhance the visual appeal and branding of the product.

Capsules

In capsule formulations, coating systems can be used to mask the taste or odor of APIs, improve stability, and enhance the visual appearance of the capsules. They can also be employed for modified release purposes, allowing for controlled release of the encapsulated drug.

Pellets/Granules

Coating systems are often used in multiparticulate dosage forms such as pellets or granules. Coatings can provide taste masking, modified release characteristics, and improve the flow properties of these multiparticulates. They enable the formulation of multi-layered coatings for achieving complex release profiles.

Conclusion

Coating system excipients are essential components in the development of solid dosage forms. They offer numerous benefits, including protection, taste masking, modified release, and visual appeal. Partnering with Protheragen-ING, a reputable supplier, ensures the availability of high-quality excipients and supports the development of stable and efficacious pharmaceutical products. If you have any excipient requirements, please contact us by phone or email, and we will respond within 2-4 working days.